Field of the Invention
This disclosure relates generally to thrust bearings and, more particularly, to self-leveling thrust bearing retainers.
Description of Related Art
Rotational bearings are well known in the art to provide an interface between a rotating structure and a contact surface. It is often common to use a pad or plurality of pads at the interface between the rotating structure and contact surface to optimize the interconnection between the bearing and the rotating structure and to transmit any axial thrust forces.
Load capacity for the bearing is often highly dependent on the pad interface in the bearing. It has been discovered that the interface can be further optimized for better transmission of axial thrust forces by tilting the pads of a bearing to create a wedge of lubricating fluid between the bearing and the rotating structure. The increased load capacity by reduced friction is achieved by increasing fluid pressure in the narrow part of the wedge. Such tilting pad thrust bearing arrangements are well known in the art. Typically, such tilting pad arrangements include an array of pads that are permitted to tilt in either one direction or two directions in a given rotational direction, thereby creating the oil wedge.
In conventional thrust bearings, however, assembly of the pads within a retainer of the bearing assembly often proves difficult. Typical tilting pad thrust bearings have retainers that require complicated machining techniques with small parts that may become loose and injected into the machine that is being used with the thrust bearing. Typical retainers for thrust bearing arrangements include a dowel or pin that is inserted into each pad and, subsequently, the retainer to keep the pad held within the retainer during assembly. U.S. Pat. No. 5,288,153 to Gardner, which is incorporated herein by reference in its entirety, shows an example of a typical thrust bearing retainer arrangement. A dowel pin is inserted into the pads and the retainer to prevent the pads from being carried circumferentially by the rotating shaft. The pads in this thrust bearing retainer arrangement, however, are capable of falling out of the notches and into the machine that is being used with the thrust bearing, which can cause significant damage to the machine.
Therefore, there is a current need for a thrust bearing retainer that permits easy assembly and retention of pads within a thrust bearing. There is also a current need for a thrust bearing retainer that will hold the thrust bearing pads in place during assembly while allowing free movement of the pads during use of the thrust bearing in a machine.